• 제목/요약/키워드: Enzyme-inhibition

검색결과 1,400건 처리시간 0.021초

한국산 녹차로부터 분리한 Flavan-3-ol 화합물의 Angiotensin Converting Enzyme 저해 효과 (Inhibition Effect of Against Angiotensin Converting Enzyme of Flavan-3-ols isolated Korean Green Tea)

  • 조영제;안봉전;최청
    • 한국식품과학회지
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    • 제25권3호
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    • pp.238-242
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    • 1993
  • 기능성 식품과 생약재로의 이용을 위한 연구의 일환으로 한국산 녹차로부터 탄닌을 분리하여 angiotensin converting enzyme 저해효과를 측정하였다. 녹차의 acetone 추출물에서 angiotensin converting enzyme 저해효과가 있음이 확인되었고 정제된 탄닌의 효소저해효과를 검토한 결과 angiotensin converting enzyme 저해는 galloyl tannin류가 nongalloyl tannin류 보다 활성이 더 우수하였고 구조적 이성체에서도 (+)-catechin류 보다 (-)-epicatechin류가 효소저해효과가 더 좋았으며, 각 물질 간 상승효과가 인정되었다. 녹차에서의 탄닌류는 angiotensin converting enzyme에 대해 비경쟁적 저해를 하는 것을 알 수 있다.

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Enantioselective N-Acetylation of 3-Amino-3-phenylpropionic Acid by Cell-free Extracts of Streptomyces neyagawaensis

  • Chung, Myung-Chul;Lee, Ho-Jae;Lee, Choong-Hwan;Chun, Hyo-Kon;Kho, Yung-Hee
    • Journal of Microbiology and Biotechnology
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    • 제7권5호
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    • pp.329-332
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    • 1997
  • Cell-free extracts of Streptomyces neyagawaensis SL-387 grown on a chemically defined medium supplemented with DL-3-amino-3-phenylpropionic acid (APP) produced N-acetyl-APP (Ac-APP) in the presence of APP and acetyl coenzyme A. The APP obtained by acid hydrolysis of the Ac-APP was D-configuration: $[\alpha]_D+6.5^{\circ}(H_2O)\;at\;20^{\circ}C$, optical purity 92% enantiomeric excesses (ee). These results suggest that an N-acetyltransferase exists in the cell-free extract as a novel enzyme with specificity for D-APP.

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Inhibition of Aminopeptidase N by 2-Hydroxy-3-amino-4-(p-nitrophenyl)butyryl Peptide Derivatives

  • Chung, Myung-Chul;Lee, Choong-Hwan;Lee, Ho-Jae;Chun, Hyo-Kon;Kho, Yung-Hee
    • Applied Biological Chemistry
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    • 제41권8호
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    • pp.608-610
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    • 1998
  • To investigate the inhibitory activity of 2-hydroxy-3-amino-4-phenylbutyrate-harboring aminopeptidase N inhibitors, p-nitro-AHPA-peptide derivatives (1 and 2) and an AHPA-peptide derivative (3) were synthesized by chain elongation from C-terminal end using DCC/HOBt as a coupling reagent. The peptides $1{\sim}3$ exerted strong inhibitory activities against aminopeptidase N with $IC_{50}$ values of 1.8, 7.3 and $24.0\;{\mu}g/ml$, respectively, and cytotoxicity on cancer cell lines in vitro.

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Inhibition of the Biodegradative Threonine Dehydratase from Serratia marcescens by ${\alpha}$-Keto Acids and Their Derivatives

  • Choi, Byung-Bum;Kim, Soung-Soo
    • BMB Reports
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    • 제28권2호
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    • pp.118-123
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    • 1995
  • Biodegradative threonine dehydratase was purified to homogeneity from Serratia marcescens ATCC 25419 by streptomycin sulfate treatment, Sephadex G-200 gel filtration chromatography followed by AMP-Sepharose 4B affinity chromatography. The molecular weight of the purified enzyme was 118,000 by fast protein liquid chromatography using superose 6-HR. The enzyme was determined to be a homotetrameric protein with subunit molecular weights of 30,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme was inhibited by ${\alpha}-Keto$ acids and their derivatives such as ${\alpha}-ketobutyrate$, pyruvate, glyoxlyate, and phosphoenol pyruvate, but not by ${\alpha}-aminobutyrate$ and ${\alpha}-hydroxybutyrate$. The inhibition of the enzyme by pyruvate and glyoxylate was observed in the presence of AMP. The inhibitory effect of glyoxylate was decreased at high enzyme concentration, whereas the inhibition by pyruvate was independent of the enzyme concentration. The kinetics of inhibition of the enzyme by pyruvate and glyoxylate revealed a noncompetitive and mixed-type inhibition by the two inhibitors with respect to L-threonine and AMP, respectively.

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Sesquicillin, an Extracellular Matrix Adhesion Inhibitor, Inhibits the Invasion of B16 Melanoma Cells In vitro

  • Lee, Ho-Jae;Chun, Hyo-Kon;Chung, Myung-Chul;Lee, Choong-Hwan;Kho, Yung-Hee
    • Journal of Microbiology and Biotechnology
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    • 제9권1호
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    • pp.119-121
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    • 1999
  • Tumor cell interaction with the extracellular matrix is defined as the critical event of tumor invasion that signals the initiation of a metastatic cascade. Sesquicillin has been identified as an inhibitor of melanoma cell adhesion to the components of the extracellular matrix (ECM) in cultured broth of fungal strain F60063. Sesquicillin strongly inhibited the adhesion of B16 melanoma cells to laminin, fibronectin, and typeIV collagen. It also inhibited B16 melanoma cell invasion of reconstituted basement membrane Matrigel in vitro in a dose-dependent manner. These results suggest that sesquicillin is a new class of nonpeptidic ECM adhesion inhibitor having anti-invasive activity.

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효소 저해법을 이용한 Carbamate계 농약의 다성분 잔류분석법 개발 (Development of Multi-Residue Methods for Carbamate Pesticides by the Enzyme Inhibition Test)

  • 김정호
    • 한국환경과학회지
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    • 제17권12호
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    • pp.1325-1330
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    • 2008
  • This study was carried out with the detection for multiresidue of the carbamate pesticide such as carbaryl and cabofuran by enzyme-inhibition method. The check time for determination of acetylcholinesterase(AChE) activity was selected at 60 sec. The AChE activity in chicken brain determined by the Ellman's method was $162{\mu}$mol/min/g protein. $I_{50}$ for AChE by carbamate pesticide with wet kit was 0.169mg/L of carbaryl and 0.089mg/L of cabofuran, respectively. The incubation time for enzyme kit with substrate kit was 30min for determination of AChE activity. Enzyme kit with substrate kit was stable at $4^{\circ}C\;and\;25^{\circ}C$ for 5 days. Limit detection concentration of carbaryl with dry kit for AChE was 0.05mg/L. The dry kit such as wet kit applied Enzyme-Inhibition(EI) method with AChE was confirmed the multi residue method to detect the carbamate pesticides.

CALMOSTINOL, A NEW CALPAIN INHIBITOR PRODUCED BY AN ACTINOMYCETE

  • Chung, Myung-Chul;Lee, Ho-Jae;Lee, Choong-Hwan;Chun, Hyo-Kon;Kho, Yung-Hee
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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    • pp.127-127
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    • 1998
  • Specific inhibitors of a calcium activated neutral protease calpain could be used for the treatment of neurodegenerative diseases, cataract and muscular dystrophy diseases because of their therapeutic effects. In the course of screening for potential calpain inhibitors from microorganisms, a new analogue of chymostatins named calmostinol was isolated from the culture filtrate of an actinomycete. The MW was determined to be 596 [(M + H)$\^$+/] by FAB-MS in glycerol matrix. The structure was elucidated to be N-[((S)-1-carboxy-2-phenylethyl)-carbamoyl]-${\alpha}$-[2- iminohexahydro-4(S)-pyrimidyl]-L-glycyl- L-valyl-phenylalaninol, by the spectroscopic methods such as NMR and MS fragmentation studies. Calmostinol exhibited strong activity against calpain while not against a Ca$\^$2+/ -independent cysteine protease papain.

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Penicillide, a Nonpeptide Calpain Inhibitor, Produced by Penicillium sp. F60760

  • Chung, Myung-Chul;Lee, Ho-Jae;Chun, Hyo-Kon;Kho, Yung-Hee
    • Journal of Microbiology and Biotechnology
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    • 제8권2호
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    • pp.188-190
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    • 1998
  • Penicillide, having a 5H, 7H-dibenzo[b,g][1,5] dioxocin-5-one skeleton, was isolated from the culture broth of Penicillium sp. F60760 as a nonpeptide inhibitor of calpain, a calcium-activated papain-like protease. The $IC_50$ value for the effect of penicillide against m-calpaln was $7.1{\mu}M$. However, penicillide did not inhibit papain at a concentration of $200{\mu}M$. These results suggest that penicillide is a new class of nonpeptide calpain inhibitor having an eight membered lactone ring.

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난황 laY 항체의 Inhibition Enzyme-Linked Immunosorbant Assay(ELISA)법을 이용한 원유내 Pseudomonas fluorscens의 신속 검출 방법 개발 (Inhibition Enzyme-Linked Immunosorbent Assay (ELSIA) for Rapid Dection of Pseudomonas fluorescens in Raw Milk using IgY)

  • 이승배;최석호;백두연
    • 한국축산식품학회지
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    • 제20권3호
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    • pp.231-235
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    • 2000
  • 원유에 존재하는 Ps. fluorescens의 균수를 신속하게 측정하기 위한 Inhibition Enzyme Linked Immunosorbant Assay (ELSIA)를 개발하기 위해 Ps, fluorescens(KCTC 2344)을 산란계에 접종하여 Ps.fluorescens에 대한 anti-Ps. fluorescens IgY 항체를 생산하고 그 항체의 역기를 ELISA로 측정한 결과 32일까지 항체 역가가 증가하였으며, 분리된 IgY 항체의 titer는 1:128,000으로 나타났다. Anti-Ps.fluorescens IgY 항체에대한 교차반응을 조사한 결과 그람양성균 Lactococcus faecalis, Staphylococcus aureus 뿐만 아니라 그람음성 균인 Achrombacter sal-monisida, Escherichia coil와도 교차반응을 거의 하지 않는 것으로 나타났다. Anti-Ps. fluo-rescens IgY 항체를 가지고 Inhibition ELISA 방법으로 Ps. fluorescens 균수를 신속한 측정할 수 있는 표준곡선을 작성한 결과 Ps. fluorescens균을 5.0$\times$$10^4$cfu/ml부터 5.0$\times$$10^{8}$cfu/ml 측정할 수 있는 것으로 나타났다.

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초미세 분쇄한 삼백초(Saururus chinensis) 추출물의 항산화, angiotensinconverting enzyme 및 xanthin oxidase 억제 활성 (Antioxidant, angiotensinconverting enzyme and xanthin oxidase inhibitory activity of extracts from Saururus chinensis leaves by ultrafine grinding)

  • 조영제
    • 한국식품저장유통학회지
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    • 제21권1호
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    • pp.75-81
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    • 2014
  • 초미세 분쇄를 하였을 때 입자가 작아질수록 추출수율이 높아져 약 2.5배 높은 추출수율을 나타내었다. 일반 분쇄한 시료 추출물에서 69.8%의 전자공여능 억제효과가 관찰되었고, 미세분쇄와 초미세분쇄 추출물에서는 각각 70.7과 83.8%의 억제효과를 나타내었다. 일반분쇄 추출물과 미세분쇄 및 초미세분쇄 후 추출물 모두 97% 이상의 높은 ABTS 억제효과를 나타내어 분쇄 방법에 따른 항산화력의 차이는 거의 없었다. 일반 분쇄한 시료 추출물 보다 미세분쇄와 초미세분쇄 추출물에서 더 높은 PF값을 확인하였으며, 50% ethanol 초미세분쇄 추출물에서 1.8 PF로 가장 높은 항산화력을 나타내었다. 미세분쇄와 초미세분쇄 추출물에서는 일반분쇄 추출물에 비해 입자크기가 작아질수록 TBARS 억제율이 높아지며, 물 추출물보다 ethanol 추출물의 효과가 더 우수한 것으로 확인되었다. Xanthin oxidase 저해의 경우 초미세분쇄 후 효소억제 증대 효과를 확인할 수 있었다. Angiotensin converting enzyme 억제활성은 일반분쇄 추출의 경우 물 추출물에서는 억제활성이 나타나지 않았고, 50% ethanol 추출물에서 24%의 억제율이 확인되었다. 또한, ethanol 추출물의 억제효과가 물 추출물에 비해 상대적으로 우수하였다. 50% ethanol 초미세분쇄 추출물에서 Staphylococcus aureus, Escherichia coli에 대해서 아주 약한 항균효과를 나타내었을 뿐 나머지 추출물에서의 항균효과는 거의 관찰되지 않았다.